ECU professor to discuss offshore drilling
GREENVILLE, NC (Mar. 2, 1993) — An East Carolina University scientist will take part in an ocean study, this summer, to discover how sea level has changed over the past 37 million years. “There is great interest now in this subject,” said Dr. Scott W. Snyder, an ECU geologist. Snyder will join a scientific team on a study project for the Ocean Drilling Program. The project, identified as Leg 150, gets underway in June at selected ocean drilling sites off the coast of New Jersey.
The research is sponsored, in part, by the National Science Foundation. “We know sea level has risen and fallen repeatedly,” Snyder said. “We know it is related to glacial changes—the melting and freezing of polar ice. But we don’t know precisely when the whole cycle of glacial activity started or the exact causes of it,” he said.
An expert on marine animal fossils, Snyder will spend two months aboard a research vessel working in an area called the New Jersey Margin. The area is along the Continental Slope where the relatively shallow bottom of the shelf begins its descent into the deep reaches of the ocean. One of the world’s best designed and equipped scientific drilling vessels, the JOIDES Resolution, will be used for the study. The vessel and its drilling tower will allow the scientists to penetrate deep into the seafloor to collect samples of fossil-rich sediment.
Snyder said the vessel’s drill rig will recover long tubes of sediment from the sea bed to serve as “yardsticks” on which to judge ocean changes over millions of years. Analysis of the sediment layers will focus on the time span from the beginning of the Oligocene epoch 37 million years ago through the more recent Miocene epoch ending about five and a half million years ago. The Miocene epoch may include the start of the most recent period of glacial activity when the world was considered an “icehouse.” Snyder will comb through the sediment to find the fossil remains of microscopic single-celled animals called “Foraminifera.” He said he will examine the skeletons of the tiny fossils to interpret the age of the different sediment layers.
“There is a lot of discussion now over when glaciation began. Some people don’t believe it goes back as far as the Oligocene epoch,” he said. “What we are going to try to do on this leg is carefully select the sites to get the most detailed picture of global sea level change during this critical interval when modern glaciation is believed to have begun.”
The New Jersey Continental Slope was selected because of its geological setting and because of the number of previous seismic studies made in the area. Snyder said seismic studies can reveal gas and oil pockets within the earth. Drilling into these deposits by accident would be dangerous to the ship and its crew. Gas, in particular, is dangerous because drilling into a pressurized gas pocket could damage or even sink the ship. This is why sites are carefully chosen to avoid any possibility of encountering petroleum deposits. The 470 foot research vessel is one of the top rated drill ships in the world. The ship uses a computer-controlled positioning system, featuring 12 powerful thrusters, to hold the ship over a specific location. It can suspend a drilling pipe in water 5 miles deep and can drill into the seafloor another 3,000 feet. The Leg 150 project off New Jersey is unusual because drill sites are in relatively shallow water. The depth at some proposed sites is only several hundred feet.